My home network connection to teh internetz is a fiber-optic line. NTT provides a modem which connects to the FO line, and then a weird router-like thing called a CTU which manages the actual internet connection, administers IP addresses to clients, and apparently has a firewall. My PC is ethernet connected to that, as is a wireless router (Apple AirPort Extreme /n).
When I connect to Xbox Live, as of last weekend, both Red Dead Redemption and Trenched are telling me I've got a Strict NAT setting on my network, which limits the number of players with whom I can connect.
My Apple wireless router is not running a firewall.
The CTU's firewall settings are set to "Low" which is one above "off"...
What else could be setting Strict NAT settings? And why would it have suddenly changed? I'd never received that message prior to last weekend.